ABSTRACT
Bitumen binders which have been used commercially for the road asphalts, roofing, and other pavements for many decades manifest several serious disadvantages. Low elasticity of bitumen results in brittleness and cracking at low temperatures while low softening point (SP) gives rise to low modulus and rutting in the summer season. The modification of bitumen with small portions of linear elastomeric polymers and block copolymers which demonstrate, as a rule, swelling or even solubility in bitumen helps to improve the low temperature properties but unable to resolve the most part of high temperature problems. Compared to these polymers, semi-crystalline polyethylenes (PE) having very low glass transition temperatures and high enough melting points could be reasonable alternative provided some obstacles are overcame. It is known that the PE/Bitumen pair is immiscible and has high interfacial tension in melt. Therefore, it is hard to prepare fine emulsion by mixing and to prevent coalescence and creaming of the PE phase in a quiescent state at high temperatures. It is clear that some surfactants must be added to this blend to solve the outlined problems.
